Strong winds and rain are expected to batter the UK today, with forecasts expecting the bad weather to last until 9pm.
This is already impacting Christmas travel plans, with some rail services in Scotland only running after specialist safety checks.
In addition, Avanti West Coast has warned of its own rail disruption between Macclesfield and Stoke, directly affecting journeys to London on the same day as many prepare to travel to visit relatives for the holiday period.
The BBC reports that 21 million trips were expected before Christmas, highlighting how disruptive the weather could be at this time of year.
With people across the country preparing to weather the storm, it's not just travel plans that are affected but also schools, as institutions close to keep children safe at home.
Where is Storm Pia affecting?
A yellow weather warning has been put in place for most of the UK for today (December 21) but the worst of the storm is expected to affect areas north of Birmingham.
All of Scotland and Northern Ireland is expected to be affected, as well as northern parts of England and Wales.
While London may not be as severely affected, travel across the UK will be impacted during the busy Christmas period, with train passengers in Scotland warned not to travel if they don't need to.
RAC spokeswoman Alice Simpson has also warned that drivers "need to be on high alert for fallen branches, and even trees", as well as other debris, with reports of trees and telephone poles falling over across the UK as the wind picks up.
The most northerly parts of the UK, such as the Shetland Islands, have already pre-emptively emptied schools, while others are preparing to close during the worst of the storm.
Which schools have been closed?
Here's a summary of which schools are officially closing due to Storm Pia at the time of writing:
- Bell's Brae Primary School
- Burravoe Primary School
- Cullivoe Primary School
- Cunningsburgh Primary School
- Dunrossness Primary School
- Fair Isle Primary School
- Foula Primary School
- Hamnavoe Primary School
- Happyhansel Primary School
- Lunnasting Primary School
- Mossbank Primary School
- Nesting Primary School
- North Roe Primary School
- Ollaberry Primary School
- Sandness Primary School
- Scalloway Primary School
- Skeld Primary School
- Sound Primary School
- Tingwall Primary School
- Urafirth Primary School
- Whiteness Primary School
- Aith Junior High School
- Baltasound Junior High School
- Mid Yell Junior High School
- Sandwick Junior High School
- Whalsay School
- Anderson High School
- Brae High School
